1. Field of the Invention
This invention relates to liquid drain valves and more particularly relates to self-venting drain valves for draining liquids under various pressures.
2. Description of the Related Art
Many applications require that accumulated liquids be drained from a container. For example, a fuel-water separator used with many types of diesel engines removes water from a fuel supply, collecting the water in a container. In order for the fuel-water separator to continue to remove water from the fuel supply, the accumulated water must be drained. To complicate matters, a pump may pressurize the fuel supply while the engine is running, but be inactive while the engine is not running.
Known drainage solutions are often overly complex, involving springs, standpipes, levers, pistons, plungers, and the like. These systems are difficult and expensive to manufacture and maintain. Many drainage solutions are designed to function under specific pressure conditions, and may not allow liquid to drain under other pressures. Drain valves that are designed to drain liquids under pressure often have difficulties draining liquids under atmospheric pressure, developing a vapor-lock. Drain valves that are designed to drain liquids under atmospheric pressure leak or squirt liquid erratically when the liquid is under more than atmospheric pressure.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that drain liquids under various pressure conditions. Beneficially, such an apparatus, system, and method would be relatively simple to manufacture and maintain.